HRV reflects the balance between your sympathetic (fight-or-flight) and parasympathetic (rest-and-digest) nervous systems. Higher HRV means your parasympathetic system is active and your body is in a state of recovery, adaptability, and resilience. Lower HRV indicates sympathetic dominance — stress, inflammation, poor recovery, or illness.
Research consistently shows that higher HRV is associated with lower cardiovascular mortality, better emotional regulation, improved cognitive function, and greater physical fitness. Conversely, low HRV predicts heart disease, diabetes complications, depression, and even post-surgical complications. It's one of the most powerful predictive health metrics available.
Your HRV is influenced by almost everything: sleep quality (the biggest factor), alcohol consumption, exercise recovery, stress, hydration, illness, and even what you ate for dinner. A single poor night of sleep can drop HRV by 20-30%. Alcohol typically tanks HRV for 24-48 hours.
Age naturally reduces HRV — a 25-year-old might have an average HRV of 60-80ms, while a 60-year-old might average 20-40ms. But within any age group, the range is enormous, and lifestyle factors explain most of the variation. Highly fit individuals often maintain youthful HRV well into their 60s and 70s.
Modern wearables (Oura Ring, Whoop, Apple Watch, Garmin) measure HRV during sleep, which is the most reliable and consistent reading. Track your 7-day trend rather than obsessing over individual readings. A consistent upward trend indicates improving health; a downward trend signals you need more recovery.
To improve HRV: prioritise sleep above all else. Practice slow breathing (6 breaths per minute for 5-10 minutes daily) — this directly stimulates the vagus nerve and is one of the fastest ways to improve parasympathetic tone. Build aerobic fitness through Zone 2 cardio. Reduce alcohol. Manage stress through meditation or breathwork. Cold exposure also acutely improves HRV. Focus on consistency — HRV responds to lifestyle patterns, not one-off interventions.
Anyone interested in evidence-based longevity strategies, health optimisation, and understanding the latest research on ageing and healthspan.
You are pregnant, breastfeeding, taking prescription medications, or have a pre-existing medical condition. This content is educational and does not replace professional medical advice.
Join thousands getting science-backed health tips every week.